Publications

The replacement of drilling fluids with cement to support and protect casing as well as hydraulically seal formation pressures has been the desire of prudent operators for seventy-five years and is to a point where welldefined mechanics of mud displacement are understood. Safety to personnel and environment, the success of an exploration program, validity of reservoir engineering calculations, and good placement control of stimulation treatments depend on well cemented casing, yet, there are still many instances of poor placement design in cementing operations.This paper is a summary of past and present work on the subject of mud displacement during cementing. Topics such as centralization, pipe movement, pipe lowering speed, drilling fluid conditioning, hole geometry, spacer design, flow rate, equivalent circulating density, job monitoring and post job evaluation, and how each apply to the mud displacement process are discussed. This work includes a mud displacement ",checklist", for use prior to and during the cementing operation. Although most of what is discussed has been presented in previous literature, this discussion will tie together all these critical points into one discussion for use by both operations and engineering personnel involved in cementing jobs.